This invention relates to a substrate polishing apparatus for polishing a surface of a substrate, including a semiconductor wafer, and operates by pressing a surface of a substrate to be polished against a polishing surface of a polishing table, and effecting a relative motion between these respective surfaces.
Conventional substrate polishing apparatuses comprise: a polishing table; a polishing pad, which functions as a polishing surface, provided on an upper surface of the polishing table; and a substrate carrier for holding a substrate to be polished. During a polishing operation, a substrate is held in place by the substrate carrier, and a surface of the substrate to be polished is pressed against the polishing surface of the polishing table, with relative motion being effected between these respective surfaces while a polishing fluid is supplied to the polishing surface.
Recent advances in semiconductor technology, including integration density, have given rise to a need for an improved substrate polishing apparatus which is able to both uniformly and efficiently polish a substrate surface.
A conventional substrate polishing apparatus suffers from a problem in that the substrate carrier for holding a substrate to be polished vibrates during a polishing operation. This vibration is caused by a frictional force generated between the substrate and polishing surfaces when polishing liquid is not supplied appropriately. This vibration affects the apparatus as a whole, and has a negative effect on production capacity. It also generates noise in a work environment.
A further problem with this prior art apparatus is that it consumes as much as 200 ml/min of slurry as polishing fluid, which makes substrate polishing operations expensive.
In view of these stated problems of the prior art apparatus, it is an object of the present invention to provide a polishing apparatus in which substrate carrier vibration does not occur, and in which an amount of polishing fluid consumed is significantly reduced.